Multipolar circuit breaker



Nov. 14, 1944. E. T. PLATZ MULTIPOLAR CIRCUIT BREAKER 2 Sheets-Sheet l Filed March 8, 1945 /Ns c/L/l 770/1/ /Ns @LA T/m/ f L25 giu/aaa? A TTORNE Y MULTIPOLAR CIRCUIT BREAKER Filed March 8, 1943 2 Sheets-Sheet 2 INVENTOR fill/@MIZ PZaZ A TTORNE Y Patented Nov. 14, 1944 MULTIPOLAR CIRCUIT BREAKER Elwood T. Platz, Detroit, Mich., assignor to Bulldog Electric Products Company, Detroit, Mich.,

a corporation of West Virginia Application March s, 1943,'serial`iz. y478,351Y

(ci. zoo- 116) 22 Claims.

This application discloses a multipolar circuit breaker having overload release latches, so constructed that all poles open on overload in any, without unlatching of any but the overloaded pole or poles, the remainder opening though remaining latched.

For an understanding of the breaker hereof, it is desirable to compare it with the breakerV shown in my prior application, Serial No. 376,036, led January 27, 1941, now Patent No. 2,330,237 of September 28, 1943. That application discloses, in Figs. 11-20 inclusive, a single pole circuit breaker having -a carrier or actuator or handle |2b pivotally mounted in a casing at 'Mb and pivotally mounting at Ilb a contactor biased by a spring 2lb engaging the contactor at point 22h, the contactor having a bimetal strip 26o interlatching the contactor and the carrier or handle at latch' point 28D. In that device, the handle, ywith the contactor latched thereto so that handle and contactor moved as a unit, can

f be rocked manually to and from circuit closingy and circuit opening positions on the handle pivot; and, when the parts are in circuit closing position, on warping of thev bimetal strip, the latch at 29h is released'and the spring biases the contactor to rock relative of the handle, the handle, however, remaining stationary in its closed circuit position, or if it moves, moving only slightly but not to an open circuit position.

When a number of such circuit breakers are combined, with adjacent handles tied together so that they may be manipulated in unison, as shown in Patent No. 2,274,159 of February 24, 1942, there is formed a multipolar breaker. The device so formed does not operate to open all the poles on overload in any one; instead, only the overloaded pole or poles will open, the others remaining closed. In each'overloaded pole, the contactor will move to open the circuit, but the handle or actuator will remain stationary; and in the other poles, lthe contactors, as well as the.

actuators or handles will also remain stationary.

In this application, I disclose a multipolar circuit breakerso constructed that on overload in any pole, all the poles will open automatically. This breaker comprises several single pole circuit breakers, each of which is generally, but not specifically, of the type shown in application Serial No. 376,036, now Patent No. 2,330,237 lof September 28, 1943, with the actuators linked together in accordance with Patent No. 2,274,159. Unlike those of application Serial No. 376,036, now Patent No. 2,330,237 of September 28, 1943, the individual circuit breakers hereof, however,

are so designed that when the latch of any one of them releases, due to an overload in the pole controlled by thatbreaker, not' only will the contactor of that breaker lmove relative toitsactuator to open the line of that pole, but in addition the actuator of that'` breaker will move to an open circuit position; since, in this multipolar breaker all actuators are tied together, the other or remaining breaker actuatorswill y' also move automatically to open their circuits as' well;

Opening of all poleson overload in any pole is a characteristic not .provided bya gang `of breakers'of application Serial No; 376,036, now Patent No. 2,330,237 of September 28, 1943, with their handles tied together inaccordance with Patent No. 2,274,159, but is provided by the construction of this application.

The changes which have been made and which enable breakers of the-typeshown in application Serial No. 376,036, nowPatent No. 2,330,237 of September 28, 1943, to operate satisfactorily for multipolar operation, as above, primarily are changes in location of the contactor pivot points and of the contactor-spring connection points, suchl as willy enable the actuators of all breakers to rock from circuit closing position to a circuit opening position in response to a release of any latch; in any breaker, a release of its latch will cause its actuator torock to circuit open position, a characteristic not true l of the breakers of application Serial No. 376,036, now Patent No. 2,330,237 of September 28, 1943. "I'hus' in this multipolar breaker, overload in any pole will cause latch release of the breaker of that pole and also shifting of the actuator of 'that p ole, and since all of the actuators of the multipolar 'breaker' are tied togethenall of them will rock simultaneously and thus-,all of the breakers will move to open circuit position simultaneously and thus a unit of several, tied together, will satisfactorily function as a multipolar breaker, open- Figs. l and 2 of the drawings show a multipolar breaker made up of several breakers tied together as by screws 8. Each breaker has a front cover 9 which closes a casing il having a compartment Il containing and clod by a rocker type cup shaped handle or actuator or carrier i2 mounted on a pivot I4 and having, in its inside walls, notches i6 which receive the ends of a pin I1 iixed to and forming part of a contactor Il, the latter' thus being carried by the handle i2. The contactor has a contact I9 mating with a stationary contact 20 mounted on the end of a ilexible terminal 20a. Each contactor is biased by a. spring 2i whose upper end engages the contactor at point 22 and whose lower end is seated in a V block 24 of the compartment iloor 25. Integrally secured to the contactor Il at its contact end is a bimetal strip 26 connected by a. flexible lead 21 to a terminal 28. The free end of each strip 26 interlatches its contactor and its actuator at point 29. Each door 25 has a contactor stop portion 3l.

The back wall of the casing is formed with a stop 4i to engage the lower edge of the handle and limit its clockwise rotation when the latch releases.

The upper or closed surface of each actuator is formed with a transverse slot 42 having undercut ends 43 receiving a tie strap 44 which is fastened to the actuators by screws II so as to tie together all of them and thus make or them a single handle or carrier.

Operation In on, Fig. 2, the several springs 2| urge the unit consisting of the actuator or carrier and the contactors interlatched thereto at 29 to rotate clockwise around pivots I4. stopping being assured by the contact engagements at I9-20.

In off, when the left end of the actuator or carrier i2 is pressed down from the on position, Fig. 2, the carrier and the contactors rock counterclockwise as a, unit around pivots i4, the parts stopping with the contactors engaging stops 30. The rocking of the springs 2i overcenter (across pivots I4) assures snap action.

Overload release-When the latch of any one breaker releases its contactor from the carrier, its spring 2l rocks its contactor on its pivot Il to move counterclockwise relative of the carrier to open its pole. Its contactor rocks in the carrier until the end of strip 26 strikes the closed wall of the carrier, whereupon the bias of its spring 2l on its contactor, still potent, rocks the carrier and its contactor as a unit on pivot i4, counterclockwise, until its contactor is stopped by its stop 30. The carrier is blocked from clockwise rotation by stop Il.

This movement of the carrier may or may not be enough to move the carrier all the way into oii" position. However, it is certainly enough to move the carrier suiciently to cause the other springs 2l to cross their centers or pivots Il, and no longer to bias the carrier to on position, but rather to bias the carrier to "ofi" position, and they so act, and in so acting, they move the carrier to ofi position. as a unit, the momentum of the moving parts, of course, aiding in such operation.

When the carrier rocks to the circuit open position, the lines on all poles will be opened automatically. However, though all oi' the poles will open, only the overloaded ones will unlatch, the remainder opening by handle movement, simulating manual operation, and not by their unlatching. In this way. opening of all poles on overload in any, is attained.

It will be observed that, by way of contrast to multipolar breakers now known, where opening of all poles on overload in any is attained by having all poles unlatch when any one unlatches, using a common latching means for all poles, in this device the result is attained, not by multipolar unlatching, but rather by multipolar handle movement, on unlatching of any pole, the remainder remaining latched.

The operation is such that any overloaded pole will open, free of the carrier. While it is intended that this will cause opening of the nonoverloaded poles, this will so operate only ii the carrier is not restrained against moving to an open circuit position. It will be seen that even ir the handle be held against movement, so that the non-overloaded poles remain closed, at least the overloaded pole or poles will open, for an overload in any pole causes unlatching oi' the contactor thereof so that it at least moves, being free of the handle by virtue oi its becoming unlatched.

During the movement of the carrier from circuit closing position to circuit opening position in response to an unlatching in any one breaker, the carrier will first be moved by a spring of an unlatched breaker acting through its contactor, to a position where the biasing springs oi latched breakers will not impart circuit closing bias to the carrier but will have moved across pivots i4 so that these springs will impart circuit opening bias to the carrier. Thereupon, the carrier will move, though in the last part of its movement it obtains no bias from the unlatched breaker spring, since the connecting element between the carrier and. that spring, namely the contactor, is no longer free to move, but on the contrary is blocked by its stop lll. Thus, the force for moving the carrier and for opening all three lines following an overload, in any one line, is obtained in the first part oi.' the carrier movement from the spring of the released breaker and in the latter part of its movement from the springs of the unreleased breakers. The ilrst part of the carrier movement involves shifting the carrier suiilciently so that the springs of the unreleased breakers shift across their pivots so that their forces change from circuit closing forces to circuit opening forces.

It will also be observed that the carrier is moved toward or to ofi position, following unlatching of any pole; if the carrier movement is complete to oil position, the abutment point 29 oi each unlatched pole will move past the latching end at 29 of the bimetal strip, which meanwhile has cooled, and the carrier will relatch itself automatically to the latching strip 26 of the unlatched pole. The operation of overload opening then will terminate not only with the handle and the contactors in "oif position but also with no pole unlatched.

If it happens that the above described relatching operation does not take place, because the carrier did not move all the way to oil position, possibly due to misalignment of parts, then relatching can be eil'ected manually by moving the carrier counterclockwise all the way to or beyond the oil position from whatever position it happens to occupy when it comes to rest.

Important structural differences between the breakers hereof and that of application Serial No. 376,036, now Patent No. 2,330,237 of September 28, 1943, are in locations of points I1 and 22. In

the breakers hereof, points l1 are far closer to pivots I4 and points 22 are considerably further from contacts I9, than in the breaker of application Serial No. 376,036, now Patent No. 2,330,237 of September 28, 1943. When points Il and 22 are in the locations shown in application Serial No. 376,036, now Patent No. 2,330,237 of September 28, 1943, the breaker handle does not shift from circuit closing position to circuit opening position on latch' release; but when the locations of points I7 and 22 are shown here, the carrier shifts, as described, on latch release and it is this factor which makes it possible to get circuit opening on all poles of a multipolar breaker due to overload in any pole, with the actuatorsh rigidly fastened or tied together, something that cannot be obtained with breakers according to Serial No. 376,036, now Patent No. 2,330,237 of September 28, 1943, even with their handles tied together ac cording to Patent No. 2,274,159.

Instead of the multipolar breaker being made up of three separate breakers with their casings and handles fastened together, it would be feasible to make a simple three compartment casing with a unitary multiple section carrier or handle, each compartment containing the necessary contact parts. However. for purposes of simplicity, it is preferred to make the multipolar breaker hereof out of three separate complete breakers, each generally, but not specifically, like the breaker of application Serial No. 376,036. now Patent No. 2,330,237 of September 28, 1943, but with the herein disclosed locations of points Il and 22, and with the several individual handles tied together rigidly to operate in unison, as a single carrier or handle.

Figs. 2, 3 show the relation of forces in the breakers of this application. Point A defines one end of spring 2l,point B defines the other end when the latch holds, point C defines that other end when the latch releases, line AB the line of a spring force when the latch holds, AC the line of spring force when the latch releases, L the moment arm of spring forcel when the latch holds, M the moment arm of spring force when the latch releases. P the center of pivot i4. From Fig. 2, it can b@ seen, that in a three pole construction hereof, the forces for moving the carrier to an open circuit position, when even one of the breakers unlatcl'ies. is greater than the forces for retaining the carrier in its closed circuit position, and thus the carrier moves to an open circuit position when even one of the breakers unlatches. This is not true of a three pole breaker made according to application Serial No. 376,036, now Patent No. 2,330,237 of September 28, 1943.

Now having described the multipolar breaker herein disclosed, reference should be had to the claims which follow for a determination of the inventions hereof.

I claim:

1. A multipolar breaker comprising a plurality of contactors, each having an overload release latch and a biasing spring, pivotal mountings and interconnection means for the contactors and springs arranged so that when the contactors are in circuit closing position, and all the latches hold, the springs bias the contactors towards circuit closing position to maintain them there, but when any latch releases, the corresponding spring will bias the corresponding contactor to an open circuit position and shift the remaining springs so that these will bias the remaining, still latched, contactors also to open circuit positions.

2. A multipolar breaker comprising a plurality of contactors, each having an overload release latch and a biasing spring, pivotal mountings and interconnection means for the contactors and springs arranged so that when the contactors are in circuit closing position, and all the latches hold, the springs bias the contactors towards circuit closing position to maintain them there, but when any latch releases, the corresponding spring will bias the corresponding contactor to an open circuit position and shift the remaining springs so that these will bias the remaining, still latched, contactors also' to open circuit positions. and manually accessible means for shifting all the contactors, when they are latched, to and from open circuit and circuit closing positions, in unison,

3. A multipolar breaker comprising a plurality.

of pivotally mounted interconnected contactors, each having an overload rrelease latch and an overcenter biasing spring, the parts being so arranged that when the contactors are in circuit closing position and all the latches hold, the springs bias thecontactors towards circuit closing to maintain them there, but when any latch releases, the corresponding biasing spring will bias the corresponding contacter to an open circuit position and at the Sametime shift the remaining springs overcenter so that these will bias the remaining, still latclied, contactors also to open circuit positions.

4. A multipolar breaker comprising a plurality of pivotally mounted interconnected contactors, each having an overload release latch and an overcenter biasing spring, the parts being so arranged that when the contactors arc in circuit closing position and all the latches hold. the springs bias the contactors towards circuit closing to maintain them there, but when any latch releases, the corresponding biasing spring 'will bias the corresponding contactor to an open circuit position and at the same time shift the remaining springs overcenter so that these will bias the remaining, still latched, contactors also to open circuit position, and manually accessible means for shifting the contactors, when they are all latched, to and from open circuit and circuit closingpcsitions, in unison.

5. A multipolar breaker comprising a plurality of pivotally mounted interconnected contactors, each having an overload release latch and an overcenter biasing spring, the parts being so arranged that when the contactors are in circuit closing position and all the latches hold, the springs bias the contactors towards circuit closing to maintain them there, but when any latch releases, the corresponding biasing spring will bias the corresponding contacter to an open circuit position and at the same time shift the remaining springs overcenter so that these will bias the remaining, still latched, contactors also to open circuit positions, and manually accessible means for shifting the springs of all the f intactors, overcenter when these are all latches, c., that the contactors shift to and from open circuit and circuit closing positions, in unison.

6. A multipolar breaker comprising a plurality of pivotally mounted contacts, cach having an overload release latch and a biasing spring, the relation of the parts being such that when the latch holds, and the spring is on one side of the contactor pivot, it biases that contactor to circuit closing position, and when it is on the other side of the contactor pivot, with the latch holding. it biases that contacter te an open circuit position, and means for interconnecting the contactors arranged se that when any one latch releases, the corresponding biasing spring will bias the corresponding contacter to an open circuit position and at the same time shift the remaining springs across their contacter pivots so that these lwill no longer bias the remaining, still latched, contactors to circuit closing position but will now bias them to open circuit position 7. A multipolar breaker comprising a plurality of pivotally mounted contacts, each having an overload release latch and a biasing spring, the relation of the parts being such that when the latch holds. and the spring is on one side of the contacter pivot, it biases that contacter te circuit closing position, and when it is on the other side of the contacter pivot, with the latch holding, it biases that contacter to an open circuit position, and means for interconnecting the contactors arranged so that when any one latch releases, the corresponding biasing spring will bias the corresponding contacter to an open circuit position and at the same time shift the remaining springs across their contacter pivots se that these will no longer bias the remaining, still latched, contactors to circuit closing position but will now bia: them to open circuit position. and manually accessible means for shiftingall the springs simul taneously across the pivots, when the latches hold, for shifting the contactors in unison te and from open circuit and circuit closing positions.

8, A multipolar breaker comprising a plurality of pivotally mounted contacts, each having an overload release latch and a biasing spring, the relation of the parts being such that when the latch holds, and the spring is on one side of the cont-actor pivot, it biasesthat contacter to circuit closing position, and when it is on the other side of the contacter pivot, with the latch holding, it biases that contacter to an open circuit position, and means for interconnecting the contactors arranged so that when any one latch releases, the corresponding biasing Spring will bias the corresponding contacter to an open circuit position and at the same time shift the remaining springs across their contacter pivots so that these will no longer bias the remaining, still latched, contactors, to circuit closing position but will new bias them to open circuit position, the interconnection means being manually accessible to enable the contactors to be shifted simultaneously to and from open circuit and circuit closing positions.

9. A multipolar breaker comprising a plurality of pivotally mounted contacts, each having an overload release latch and a biasing spring, the relation el the parts being such that when the latch holds, and the spring is n one side of the contacter' pivot, it biases that contacter to circuit closing position, and when it is on the other side of the contacter pivot, with the latch holding, it biases that contacter to an open circuit position, and means for interconnecting the contactors arranged so that when any one latch releases, the corresponding biasing spring will bias the corresponding contacter to an open circuit position and at the same time shift the remaining springs across their contacter pivots so that these will no longer bias the remaining, stili latched, contactors, to circuit closing position but will now bias them to open circuit pesition, and manually accessible means for shifting the contactors simultaneously, when the latches held, to and from open circuit and circuit closing positions.

10. A multipolar breaker comprising a plurality of pivotally mounted contacts, each having an overload release latch and a biasing spring, the relation of the parts being such that when the latch holds, and the spring is on one side of the contacter pivot, it biases that con taeter to circuit closing position, and when it is on the other side of the contacter pivot, with the latch holding, it biases that contacter to an open circuit position, and means for interconnecting the centactors arranged so that when any one latch releases, the corresponding biasing sprinl will bias the corresponding contacter to an open circuit position and at the same time shift the remaining springs across their contacter pivots so that these ne longer will bias the remaining, still latched, contactors to circuit closing position but will new bias them to open circuit position, the interconnection means being manually accessible to enable it to be shifted for shifting the springs across their contacter pivots and thus shift the contacters in unison to and from open circuit and circuit closing positions.

1l. A multipolar breaker having a plurality of interconnected pivoted contactors, each having an overload release latch and a biasing spring, arranged for overcenter operation, that is to say, when a spring is on one side of its contactor pivot, it biases its contacter to circuit closing position, and when it is on the other side of its contacter pivot, it biases its contacter to open circuit position, the pivots and springs being so located that the open circuit moment arm of each spring is considerably greater than its closed circuit moment arm, whereby when any one spring moves across its contacter pivot, from circuit closing biasing position to open circuit biasing position, on unlatching or release of its contacter. it not only shifts its contacter to open circuit position but also overcomes the circuit closing bias of the remaining springs, of the contactors still latched, and shifts these springs across their contacter pivots to causo their contactors also to move te open circuit position.

12. A multipolar breaker having a plurality of interconnected pivoted contactors, each having an overload release latch and a biasing spring, arranged for overcenter operation, that is te say, when a spring is on one side of its contacter pivot, it biases its contacter to circuit closing position, and when it is on the other side of its contacter pivot, it biases its contacter to open circuit position, the pivots and springs being so located that the open circuit moment arm of each spring is considerably greater than its closed circuit moment arm, whereby when any one spring moves across its contacter pivot, from circuit closing biasing position te open circuit biasing position, on unlatching er release of its contacter, not only shifts its contacter to open circuit. position but also overcomes the circuit closing bias of the remaining springs, of the contactors still latched, and shifts these springs across their contacter pivots to cause their contactors also to move to open circuit position, and manually accessible means for shifting the centactors simultaneously te and from open circuit and circuit closing positions.

13. A multipolar breaker having a plurality of interconnected pivoted contactors, each having an overload release latch and a biasing spring, arranged for overcenter operation, that is to say, when a spring is en one side of its contacter pivot,

it biases its contacter to circuit closing position,

andwhen itisv on the other side of its contacter" tion, thepivots and springs being so located thatr the open circuit moment `arm of each spring is considerably'greater than its closed circuit moment arm, whereby when any one spring moves across its contacter pivot, yfrom circuit closing biasing position to open circuit biasing'positien, on unlatching or release of its contacter, not only shifts its contacter to open circuit position but also overcomes the circuit closing bias of the remaining springs, of the contactors still latched, and shiftsthese springs across; their contacter pivots to` cause their contactors also to move to open circuit position, and manuallyaccessible means for shiftingthe springsv overcentenwhen the contactorspare latched, to cause the contactors to move simultaneously to and from open circuit and circuitclosing positionsQ 14'. Aprnultipolar circuit breaker comprising a pivotally'vmounted carrier, a plurality of independent cont'actors independently pivoted thereon and also 'independently interlatched therewith, and a plurality of independent biasing springs independently engaging and biasing the contactors,

each 'spring being arranged to bias its own con-v taeter and the carrier interlatched therewith and the remaining contactors interlatched with the carrier, when the latches hold, in a circuit closing direction, and,when its latch releases, to bias its ewncontactor, and the carrier, and the remaining contactors still latched to the carrier, in an opposite or circuitbpening direction, each spring,

on release of its latch, first biasing its contacter te move'relative to the carrier in the circuit opening direction, and then crossing theA pivotal mounting er the carrier, and then biasing the carrier yin the circuit opening direction, thereby to bias the other contactors, as well as its own', to" move for circuit opening upon release of its own latch. Y

l5. A multipolar circuit breaker comprising a pivotally ,mounted carrier, a plurality of independent contactors` independently pivoted thereon and also independently interlatched therewith, and a plurality of independent biasing springs independently engaging and biasing the contactors, each spring being arranged to bias its own contacter and the carrier interlatched therewith and the remaining contactors interlatched with the carrier, when the latches hold, in a circuit closing direction, and, when its latch releases, to bias its own contacter, and the carrier, and the remaining contactors still latched to the carrier. in an opposite or circuit opening direction, each spring, on release of its latch, first biasing its contacter to move relative to the carrier in the circuit opening direction, and then crossing the pivotal mounting of the carrier, and then biasing the carrier in the circuit opening direction, thereby to shift the springs of the remainng crtntactors out ofthe position wherein they exert circuit closing bias and into a position wherein they exert circuit opening bias, these then biasing the other contactors, as well as the carrier, to move in the circuit opening direction.

16. A multipolar circuit breaker comprising` a pivotally mounted carrier, a plurality of independent contactors independently pivoted thereon and also independenthT interlatched therewith, and

the remaining contactors interlatched with the carrier, when the latches hold, in a circuit closing direction, and, when its latch' releases, to bias its own contacter, and the carrier,` and the remaining contactors still latched to the carrier, in an opposite or circuit opening direction, each spring, on release yof its latch, first biasing its contacter to move relative to the carrier in the circuit opening direction, and then crossing the pivotal mounting of the carrier, and then biasing the carrier in the circuit opening direction, thereby to bias the other contactors, as well as its own, to move for circuit opening upon release of its own latch, the carrier being manually accessible so te be shifted, with its springs and its 'contactors latched thereto, to and from circuit opening and closing positions.

17. A multipolar circuit breaker comprising a pivotally mounted carrier, a plurality of independent contactors independently pivoted thereon and also independently linterlatched therewith, and a pluralityl of independent biasing springs independently engaging and biasing the contactors, each spring being arranged to bias its own contacter and the carrier interlatched therewith and the remaining contactors interlatched with the carrier. when the latches hold, in a circuit closing direction, and, when its latch releases, to bias its own contacter, and the carrier, and the remaining contactors still latched to the carrier, in an opposite or circuit opening direction, each spring, on release of its latch, first biasing its contacter to move rela-tive to the carrier in the circuit opening direction, and then crossing the pivotal mounting of the carrier, and

then biasing the carrier in the circuit opening a plurality of independent biasing springs independently engaging and biasing the contactors, each spring being arranged to bias its own contacter and the carrier interlatched therewith and direction, thereby to shift the springs of the remaining contactors eut of the position wherein they exert circuit closing bias and into a pesition wherein they exert circuit opening bids, these then biasing the other contactors, as well as the carrier, to move in the circuit opening direction, the carrier being manually accessible so as to be shifted, with its springs and its contactors latched thereto, to shift the springs across the contacter pivots whereby the contactors move te and from circuit opening and closing positions.

18. A multipolar circuit breaker comprisinga pivotally mounted carrier, a plurality of independent contactors independently pivoted thereon and also independently interlatched therewith, and la plurality of independent biasing `springs independently engaging and biasing the contactors, each spring being arranged to bias its own contacter and the carrier interlatched therewith and the remaining contactors interlatched with the carrier, when the latches hold, in a circuit closing direction, and, when its latch releases, to biasits own contacter, and the carrier, and the remaining contactors still latched to the carrier, in an opposite or circuit opening direction, each spring. on release of its latch, first biasing its contacter to move relative to the carrier in the circuit opening direction, and then crossing the pivotal mounting of the carrier, and then biasing the carrier in the circuit opening direction, thereby to bias the other contactors, as well as its own, to move for circuit opening upon release of its'own latch, the carrier being manually accessible so to be shifted, with its springs and its contactors latched thereto, to and from circuit opening and closing positions.

19. A multipolar breaker comprising a plurality of contactors, each having an overload release latch and a biasing spring, pivotal mountings and interconnection means for the contactors and springs arranged so that when the contactors are in circuit closing position, and all the latches hold, the springs bias the contactors towards circuit closing position to maintain them there, but when any latch releases, the corresponding spring will bias the corresponding contactor to an open circuit position and shift the remaining springs so that these will bias the remaining, still latched, contactors also to open circuit positions, and relatch every released latch automatically.

20. A multipolar breaker comprising a plurality of contactors, each having an overload release latch and a biasing spring, pivotal mountings and interconnection means for` the contactors and springs arranged so that when the contactors are in circuit closing position, and all the latches hold, the springs bias the contactors towards circuit closing position to maintain them there, but when any latch releases, the corresponding spring will bias the corresponding contactor to an open circuit position and shift the remaining springs so that these will bias the remaining, still latched, contactors also to open circuit positions, and relatch every released latch automatically, and manually accessible means for shifting all the contactors, when they are latched, to and from open circuit and circuit closing positions, in unison.

2l. A multipolar circuit breaker comprising a pivotally mounted carrier, a plurality of independent contactors independently pivoted thereon and also independently interlatched therewith, and a plurality of independent biasing springs independently engaging and biasing the contactors, each spring being arranged to bias its own contactor and the carrier interlatched therewith and the remaining contactors interlatched with the carrier, when the latches hold, in a circuit closing direction, and, when its latch releases, to bias its own contactar, and the carrier, and the remaining contactors still latched to the carrier, in an opposite or circuit opening direction, each spring, on release of its latch, rst

biasing its contactor to move relative to the carrier in the circuit opening direction, and then crossing the pivotal mounting of the carrier, and then biasing the carrier in the circuit opening direction, thereby to shift the springs of the remaining contactors out of the position wherein they exert circuit closing bias and into a position wherein they exert circuit opening bias, these then biasing the other contactors, as well as the carrier, to move in the circuit opening direction, and also relatching the unlatched contactar to the carrier.

22. A multipolar circuit breaker comprising a pivotally mounted carrier, a plurality of independent contactors independently pivoted thereon and also independently interlatched therewith, and a plurality of independent biasing springs independently engaging and biasing the contactors, each spring being arranged to bias its own contactor and the carrier interlatched therewith and the remaining contactors interlatched with the carrier, when the latches hold, in a circuit closing direction, and, when its latch releases, to bias its own contacter, and the carrier, and the remaining contactors still latched to the carrier, in an opposite or circuit opening direction, each spring, on release of its latch, first biasing its contactor to move relative to the carrier in the circuit opening direction, and then crossing the pivotal mounting of the carrier, and then biasing the carrier in the circuit opening direction, thereby to bias the other contactors, as well as its own., to move for circuit opening upon release of its own latch, the carrier being manually accessible so to be shifted, with its springs and its contactors latched thereto, to and from circuit opening and closing positions, the unlatched contactor moving free of the carrier when its latch releases, so that it can open its circuit, even though the carrier beheld against movement, and even though the remaining, still latched, contactors are thereby held against open circuit movement.

ELWOOD T. PLATZ. 

